This is polymer joint sand.
It is reinforced with plastic and hardens slightly. Available at building material suppliers or in well-stocked hardware stores in 25kg (55 lb) bags.
It is sold as a single-component or two-component system. When applying, it is important to work carefully to avoid any residues on the stones later.
It is reinforced with plastic and hardens slightly. Available at building material suppliers or in well-stocked hardware stores in 25kg (55 lb) bags.
It is sold as a single-component or two-component system. When applying, it is important to work carefully to avoid any residues on the stones later.
M
mario.w33322 Sep 2009 15:15Oh yes, I know that problem well. I've even considered pouring concrete just to avoid having weeds growing between the joints! And this polymer joint sand really helps somewhat – have you had any experience with it?
There are several options.
In our company, PCI Pavifix or GfK paving joint filler has proven effective.
You don’t even need to grout it. It's enough to pre-wet the surface. The material is swept in, rinsed off, allowed to cure, and that’s it. The remaining haze fades away on its own over time.
It is important that the paving is installed on a gravel base. On concrete substrates, it is not recommended because the material allows water to pass through.
With a gravel base, this means "no more frost damage." On concrete slabs, it means moisture can get in but not out, and you may have to remove your slabs again next spring.
Best regards,
Silvio79
In our company, PCI Pavifix or GfK paving joint filler has proven effective.
You don’t even need to grout it. It's enough to pre-wet the surface. The material is swept in, rinsed off, allowed to cure, and that’s it. The remaining haze fades away on its own over time.
It is important that the paving is installed on a gravel base. On concrete substrates, it is not recommended because the material allows water to pass through.
With a gravel base, this means "no more frost damage." On concrete slabs, it means moisture can get in but not out, and you may have to remove your slabs again next spring.
Best regards,
Silvio79
Yes, the weeds are gone, but unfortunately so is the beauty of the slabs/stones...
This summer, we installed a new terrace of about 40m² (430ft²) with slabs and afterwards swept in the polymer jointing sand from Semin according to the manufacturer’s instructions (conditions: around 35°C (95°F), bright sunshine, dry light-colored slabs, cleanly sweeping the polymer jointing sand into the joints, carefully moistening with a watering can, letting it cure, then sweeping away any leftover material). We then experienced our blue wonder: the jointing sand left an ugly gray haze on the previously beautifully light slabs, consisting of tiny particles that simply turned all the light-colored slabs gray.
But no problem, no reason to panic: the packaging said any leftover material would disappear over time.
Several days later – especially after some rain showers – the “new terrace” still looked just as embarrassing. The friendly staff at the building supply store where we bought this product from Semin seemed familiar with the issue and put us in touch with the manufacturer. The manufacturer reassured us, referring to a “very special product” they would send us that could easily remove the gray haze. However, they did not have this magic solution in stock and had to order it first. The product would just need to be sprayed on the slabs with a watering can, waited on for about 1-2 minutes, and then the gray haze could be “easily scrubbed away.” When we asked how this problem could happen at all, they blamed “residual moisture” from morning dew or similar (??? at 35°C (95°F)???). So we patiently waited for the “miracle cure” for our completely ruined terrace (there are some lovely pictures available on request).
About four weeks and roughly three puzzled calls with the manufacturer later, the long-awaited miracle product arrived. Three containers with French labels and corresponding warnings... To our great surprise, it turned out to be a simple cement residue remover (what a special product, taking this long to arrive!). We applied it, waited... and as it turned out, nothing scrubbed off! Somewhat desperate, we tried to contact Semin again, but with little success. Thanks to the helpful employee at the building supply store, we finally got a callback... They said they couldn’t understand the problem, promised to change the manufacturer’s instructions, and said we would receive compensation. The costs for the polymer jointing sand and all additional expenses would be reimbursed.
Meanwhile, we had bought six containers of cement residue remover and steel brushes at the building supply store. After many hours of working on all fours, scrubbing the slabs covered with gray haze until they brightened up again like at the beginning.
We are still waiting for compensation today (almost 4 months later). After many cleverly evasive phone calls (like “we sent you a refund check – did it not arrive?” and so on), I think it’s important to raise awareness about this issue in general. I also now know that this is a fundamental problem with the product itself (see the beautiful pedestrian zone in Schweinfurt, for example – a wonderful gray haze on all the slabs!, etc.).
Of course, the manufacturer has not changed their processing instructions. We spent a lot of money on cement residue remover and steel brushes, our knees hurt for days, and our hands were sore from scrubbing... The manufacturer Semin is far away in France, so nothing seems to affect them...
Our conclusion: Stay away from this polymer jointing sand, stay away from the company Semin – unless you have no high expectations of visual beauty or you enjoy delays and sore body parts... clearly... no more weeds will grow there either!
This summer, we installed a new terrace of about 40m² (430ft²) with slabs and afterwards swept in the polymer jointing sand from Semin according to the manufacturer’s instructions (conditions: around 35°C (95°F), bright sunshine, dry light-colored slabs, cleanly sweeping the polymer jointing sand into the joints, carefully moistening with a watering can, letting it cure, then sweeping away any leftover material). We then experienced our blue wonder: the jointing sand left an ugly gray haze on the previously beautifully light slabs, consisting of tiny particles that simply turned all the light-colored slabs gray.
But no problem, no reason to panic: the packaging said any leftover material would disappear over time.
Several days later – especially after some rain showers – the “new terrace” still looked just as embarrassing. The friendly staff at the building supply store where we bought this product from Semin seemed familiar with the issue and put us in touch with the manufacturer. The manufacturer reassured us, referring to a “very special product” they would send us that could easily remove the gray haze. However, they did not have this magic solution in stock and had to order it first. The product would just need to be sprayed on the slabs with a watering can, waited on for about 1-2 minutes, and then the gray haze could be “easily scrubbed away.” When we asked how this problem could happen at all, they blamed “residual moisture” from morning dew or similar (??? at 35°C (95°F)???). So we patiently waited for the “miracle cure” for our completely ruined terrace (there are some lovely pictures available on request).
About four weeks and roughly three puzzled calls with the manufacturer later, the long-awaited miracle product arrived. Three containers with French labels and corresponding warnings... To our great surprise, it turned out to be a simple cement residue remover (what a special product, taking this long to arrive!). We applied it, waited... and as it turned out, nothing scrubbed off! Somewhat desperate, we tried to contact Semin again, but with little success. Thanks to the helpful employee at the building supply store, we finally got a callback... They said they couldn’t understand the problem, promised to change the manufacturer’s instructions, and said we would receive compensation. The costs for the polymer jointing sand and all additional expenses would be reimbursed.
Meanwhile, we had bought six containers of cement residue remover and steel brushes at the building supply store. After many hours of working on all fours, scrubbing the slabs covered with gray haze until they brightened up again like at the beginning.
We are still waiting for compensation today (almost 4 months later). After many cleverly evasive phone calls (like “we sent you a refund check – did it not arrive?” and so on), I think it’s important to raise awareness about this issue in general. I also now know that this is a fundamental problem with the product itself (see the beautiful pedestrian zone in Schweinfurt, for example – a wonderful gray haze on all the slabs!, etc.).
Of course, the manufacturer has not changed their processing instructions. We spent a lot of money on cement residue remover and steel brushes, our knees hurt for days, and our hands were sore from scrubbing... The manufacturer Semin is far away in France, so nothing seems to affect them...
Our conclusion: Stay away from this polymer jointing sand, stay away from the company Semin – unless you have no high expectations of visual beauty or you enjoy delays and sore body parts... clearly... no more weeds will grow there either!
I can also tell you right away where the problem was.
The conditions you described are great for sunbathing, swimming, walking, and just having a nice day in general.
However, when carrying out this kind of work, it’s too warm because the material sets immediately. In your case, it already happened directly on the panels. If there is still no shade, you can add another 10 degrees to that.
The warmer it is, the worse it gets. And removing that haze is truly no fun. I’m actually surprised it could be removed with cement residue remover.
I think this shows that there are things, especially when it comes to reactive materials, that are probably better left to the professionals to avoid this kind of trouble.
The conditions you described are great for sunbathing, swimming, walking, and just having a nice day in general.
However, when carrying out this kind of work, it’s too warm because the material sets immediately. In your case, it already happened directly on the panels. If there is still no shade, you can add another 10 degrees to that.
The warmer it is, the worse it gets. And removing that haze is truly no fun. I’m actually surprised it could be removed with cement residue remover.
I think this shows that there are things, especially when it comes to reactive materials, that are probably better left to the professionals to avoid this kind of trouble.
everl71 schrieb:
...and the "professional" only works at temperatures between 15 and 25 degrees Celsius? Well, I can only speak for us, but we actually try to avoid working outside in higher temperatures. And if it’s unavoidable, we try to build a small sunshade to protect against direct sunlight. That’s because the material reacts immediately.
We don’t really have any other choice.
everl71 schrieb:
...That definitely wasn’t the reason; the nice gentlemen who worked on the Schweinfurt pedestrian zone with exactly that material are professionals... and there are many other professionals we have since been in contact with.
It simply comes down to the material: there is good and bad material. This was bad, even though it wasn’t cheap. A pity...
And the cement residue remover only worked in combination with "vigorous scrubbing," thank goodness it could be removed at all. So: not only the professional but also the product are essential factors for effective weed control between slabs and stones...I’m glad to hear you managed to fix it. That’s the most important thing. I’ll just give you one small tip:
When you do projects like this, don’t go to a hardware store, because they usually don’t really know what they’re selling. Go to a specialist supplier, preferably one that also uses these materials in construction. They know exactly which products are suitable for amateurs, and they can advise and support you regarding “professional materials,” which this sand definitely is, so that issues like this don’t happen. You can also expect that they don’t sell poor-quality materials if they use them themselves.
And specialist suppliers don’t have to be more expensive. Brands like PCI, Schluter, and others are usually cheaper at specialist stores than at hardware chains. And you get advice, not just a “... this should work...” response...
Best regards
Silvio
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